Fluid flow control providing increased energy extraction

Abstract

Systems and methods configured to control ambient fluid flow for increased energy extraction using a turbine are disclosed. In various examples, a system can include a convergent nozzle configured to receive and accelerate an ambient flow of fluid and a turbine including one or more rotor blades. The convergent nozzle can include a configuration having a ratio of a nozzle inlet area to a nozzle outlet area between about 1.5:1 to about 10:1, inclusive. An interior nozzle surface can include one or more contours aligned with a direction of the ambient flow of fluid. The convergent nozzle can include apertures in a region near a nozzle outlet. The apertures can be selectively controlled to draw additional fluid flow into the accelerated flow to avoid excessive stress on turbine components. The rotor blades can have a length equal to or slightly greater than a radius of the nozzle outlet.

1 . A system, comprising:
 a convergent nozzle configured to receive and accelerate an ambient flow of fluid; and   a turbine including a rotor, the rotor configured to convert kinetic energy of the accelerated flow of fluid into mechanical energy suitable to drive an energy extraction device.   
     
     
         2 . The system of  claim 1 , wherein the energy extraction device includes an electric generator or a hydraulic pump. 
     
     
         3 . The system of  claim 1 , wherein the convergent nozzle includes a configuration having a ratio of a nozzle inlet area to a nozzle outlet area between about 1.5:1 to about 10:1, inclusive. 
     
     
         4 . The system of  claim 1 , further comprising a platform configured to align the convergent nozzle and the rotor with a direction of the ambient flow of fluid. 
     
     
         5 . The system of  claim 4 , wherein an interior surface of the convergent nozzle includes a contour configured to be aligned with the direction of the ambient flow of fluid, the contour being defined using a reference line extending a length of the convergent nozzle, from a focal point of a nozzle inlet to a focal point of a nozzle outlet, with a reference point being about one half the distance along the reference line, a circumference of the interior surface of the convergent nozzle at each point, L Rx , along the reference line defined by,
   Circumference=2π( R   O +( C/ 2)+ C *[( L   Rx   *|L   Rx |)]/ L   2   IO ) and
   Intended Factor of Acceleration=((2C/R O )+(C 2 /R 2   O ))+1, where L Rx  is a positive amount if, from the reference point, the point at which the circumference is being determined is the distance along the reference line starting at the reference point in a direction toward the nozzle inlet, and L Rx  is negative where it is the distance along the reference line from the reference point in a direction toward the nozzle outlet, R I  is the radius of the convergent nozzle at the nozzle inlet, R O  is the radius of the convergent nozzle at the nozzle outlet, C is the difference R I -R O , and L IO  is the length of the convergent nozzle determined along the reference line.   
     
     
         6 . The system of  claim 1 , further comprising one or more ducts positioned within the convergent nozzle, the ducts configured to create one or more zones with a differing fluid velocity at a nozzle outlet relative to an adjacent zone. 
     
     
         7 . The system of  claim 1 , wherein the convergent nozzle includes a material selected from the group consisting of: aramid, liquid crystal polymer, ultra-high strength polyethylene, and carbon fiber. 
     
     
         8 . The system of  claim 1 , wherein the rotor includes one or more rotor blades having a length about equal to or slightly larger than a radius of a nozzle outlet. 
     
     
         9 . The system of  claim 8 , wherein at least one of the one or more rotor blades includes a blade tip turned at an angle to a longitudinal extension of the corresponding rotor blade, the angle oriented in a direction toward an airfoil surface experiencing lift. 
     
     
         10 . The system of  claim 8 , wherein at least one of the one or more rotor blades includes a blade tip having a plate positioned perpendicular to a longitudinal extension of the corresponding rotor blade. 
     
     
         11 . The system of  claim 8 , wherein at least one of the one or more rotor blades includes a wedge-like shape on a leading edge of an airfoil to reduce vortices at a blade tip. 
     
     
         12 . The system of  claim 8 , wherein an asymmetric camber of the one or more rotor blades becomes more symmetric with respect to each blade's chord and distance away from a rotor hub until it is substantially symmetric near a blade tip, and wherein a length of the chord gradually increases with distance away from the rotor hub. 
     
     
         13 . The system of  claim 12 , wherein the camber, the length of the chord, and an angle with respect to a plane of rotation of each rotor blade is adjustable, in a continuous or a discontinuous manner, to correspond to a fluid velocity at the nozzle outlet created by one or more ducts positioned within the convergent nozzle or an external annular ring, having airfoil characteristics, positioned about a circumference of a nozzle inlet or the nozzle outlet. 
     
     
         14 . The system of  claim 12 , wherein the rotor hub includes an annular disc centered on a shaft driving the energy extraction device, the one or more rotor blades being adjustably coupled to the rotor hub in such a way to allow for modification of an attack angle of each rotor blade's airfoil. 
     
     
         15 . The system of  claim 8 , wherein the one or more rotor blades are directly or indirectly coupled to a shaft driving the energy extraction device using a rope of inelastic material, the rope configured to redirect rotational forces on the one or more rotor blades. 
     
     
         16 . The system of  claim 8 , further comprising an external annular ring, having airfoil characteristics, positioned about a circumference of a nozzle inlet or the nozzle outlet. 
     
     
         17 . The system of  claim 16 , wherein the airfoil includes a greater circumference on a leading inlet edge than on a trailing outlet edge and is positioned from the nozzle outlet at a distance approximately equal to its camber. 
     
     
         18 . The system of  claim 1 , wherein the convergent nozzle includes one or more apertures in a region near a nozzle outlet. 
     
     
         19 . The system of  claim 18 , wherein the one or more apertures are selectively controllable such that, as the accelerated flow of fluid reaches or exceeds a preselected velocity, the apertures are opened to draw additional fluid flow into the accelerated fluid flow and modulate such accelerated flow to avoid excessive stress on the rotor. 
     
     
         20 . A method, comprising:
 accelerating an ambient flow of fluid, including funneling the ambient flow of fluid into and through a convergent nozzle to a rotor of a turbine; and   driving an energy extraction device, including one or both of an electric generator or a hydraulic pump.   
     
     
         21 . The method of  claim 20 , further comprising transmitting power captured by driving the hydraulic pump to a hydraulic accumulator or a hydraulic motor attached to the electric generator. 
     
     
         22 . The method of  claim 21 , further comprising capturing heat energy from the sun or waste heat from an exothermic process and transmitting the heat energy to the hydraulic accumulator using a heat transfer fluid and a heat exchanger. 
     
     
         23 . The method of  claim 22 , further comprising transmitting energy from the hydraulic accumulator to a central system including one or more hydraulic motors attached to one or more electric generators. 
     
     
         24 . The method of  claim 20 , wherein funneling the ambient flow of fluid into and through the convergent nozzle includes accelerating the ambient flow of fluid at a ratio between about 2.5:1 to about 7:1, inclusive. 
     
     
         25 . The method of  claim 20 , further comprising positioning the convergent nozzle on a platform, including rigidly securing the convergent nozzle to the platform and mounting the platform to a tower such that the convergent nozzle and platform orientate a nozzle inlet with a direction of the ambient flow of fluid. 
     
     
         26 . The method of  claim 20 , wherein accelerating the ambient flow of fluid includes accelerating an ambient flow of wind or an ambient flow of water. 
     
     
         27 . The method of  claim 20 , further comprising coupling one or more rotor blades to a rotor hub centered on a drive shaft of the energy extraction device, including enabling rigging affixed to the rotor hub and between individual rotor blades to transmit angular forces on the rotor blades to the rotor hub. 
     
     
         28 . The method of  claim 27 , wherein coupling the one or more rotor blades to the rotor hub includes coupling the rotor blades to the rotor hub in a range from (a) each blade being perpendicular to the hub at the point of connection to (b) each blade being displaced up to 0.10 radians from a tangential point at which the blade extends perpendicularly. 
     
     
         29 . The method of  claim 20 , further comprising coupling one or more rotor blades to a rotor hub mounted on a releasable roller clutch, the roller clutch, when engaged, powering a drive shaft coupled to the energy extraction device.